Blonde jokes may very well disappear after this study. As crazy and perhaps unnecessary as it may seem, this study demonstrates that blonde women aren’t any less intelligent than brunettes and redheads. The study carried out by Jay L. Jagorsky at the University of Ohio, developed in order to fight discrimination, has demonstrated that blondes may actually have higher IQs than others. Let’s take a closer look…

The research published in Economics Bulletin was initiated to address the problem of discrimination based on appearance and its significant economic consequences. Blonde women are often the victim of negative stereotypes (stupidity, naiveté, incompetence). These stereotypes are strengthened by popular culture, particularly in films (think of Marilyn Monroe in Gentlemen Prefer Blondes). “Blondes," like certain other segments of the population, are the butt of many jokes. But the stereotypes have an impact on hiring practices, salaries, and promotions. For Jay L. Jagorsky, the issue was in urgent need of clarification. He wanted to prove that when it comes to the question, “Are blonde women less intelligent than others?” the answer is no.

The authors based their study on a cohort of the National Longitudinal Survey of Youth 1979 (NLSY79), a large panel that is representative of the national population, developed at the time to follow baby boomers. People who were between the ages of 14 and 21 in 1979 are often interviewed to analyze the impact of education, professional experience, and other factors. In 1985, in order to avoid others responding in place of a participant, a question about natural hair color was added to the questionnaire. 10,878 replied. IQ tests were available for most of the respondents. The AFQT (Armed Forces Qualification Test) is used by the Pentagon to determine the IQ of its recruits and consists of lexical knowledge tests, reading comprehension, mathematics and arithmetic reasoning. Jay L. Jagorsky then crossed these two variables: hair color and IQ.

Here’s what he found: blonde women had an average IQ of 103.2 points, compared to brunettes (102.7) and redheads (101.2). The IQ difference between blondes and brunettes was not statistically significant. We can’t say with certainty that blondes are smarter, but we can say that they aren't less intelligent. They are also overrepresented among those with an exceptionally high IQ. Indeed, 4.3% of blondes (in this cohort) had IQs over 125, compared to 4% of brunettes.

And for you, gentlemen, the results are reversed: men with brown hair had higher IQs (104.4) than blonds (103.9) and redheads (100.5). Finally, for very high IQs, blonds again come out on top (5.4%) ahead of redheads (5.3%) and men with brown hair (4.9%).

In conclusion, this study may make life quite a bit harder for comedians!